A method for manufacturing a vitreous silica crucible includes, for example, a silica powder layer forming process of forming a silica powder layer by depositing silica powder having an average particle diameter of approx. 300 um on the inner surface of a rotating mold and an arc-fusing process of forming a vitreous silica layer by arc-fusing the silica powder layer while depressurizing the silica powder layer from the mold side (this method is called rotational molding).
In this arc-fusing process, initially, a transparent vitreous silica layer (hereafter referred to as a “transparent layer”) is formed by strongly depressurizing the silica powder layer to remove bubbles; and thereafter, a bubble-containing vitreous silica layer where bubbles remain (hereafter referred to as a “bubble-containing layer”) is formed by weakly depressurizing the silica powder layer. Thus, a two-layer vitreous silica crucible including the inner transparent layer and the outer bubble-containing layer is formed.
On the other hand, in order to manufacture a silicon single crystal by pulling it by use of a vitreous silica crucible by the Czochralski method, there have been actively developed methods for performing numerical analysis on the shape of the solid-liquid interface between a silicon single crystal, which is a solid, and a silicon melt, which is a liquid, or the temperature distribution around the solid-liquid interface through a computer simulation.
For example, Patent Document 1 discloses that property values of members in a hot zone modeled using a mesh structure are inputted to a computer and then the surface temperature distribution of each member is obtained based on the amount of heat generated by a heater and the emissivity of each member.